Thanks to recent work from Tom Trenka, Dan Pupius and others, Dojo now supports widgets in Firefox 1.5 Beta with native rendering! This works in a mixed namespace environment, so embed your SVG widgets inside your XHTML markup, and voila. You get the benfits of the Dojo widget system, with the power of the SVG drawing and rendering model. No examples yet, but the work I have seen so far from a corporate user are really nice.